Luminous acoustical ceiling



April 4, 1961 M. c. ROSENBLATT 2,978,571

LUMINOUS ACOUSTICAL CEILING Filed July 31, 1956.

ATTORNEYS United States Patent LUMINOUS ACOUSTICAL CEILING Maurice C. Rosenblatt, 91 Central Park West, New York, NY.

Filed July 31, 1956, Ser. No. 601,185

Claims. (Cl. 240 9) This invention relates to ceilings of buildings and more especially to hung ceilings made of translucent material, such as plastic sheets located below fluorescent lighting fixtures to produce a luminous ceiling area. The invention relates to constructions for improving the appearance, and the acoustical and ventilating qualities of ceilings of the character indicated.

One object of the invention is to provide a luminous ceiling having any desired predetermined degree of sound absorption, and it is a feature of the invention that this result is attained without any disfigurement of the appearance or effectiveness of the luminous ceiling.

Another object is to combine available and inexpensive materials to provide satisfactory acoustics as well as good air conditioning, circulation and distribution with a hung ceiling having a uniform, glare-free, diffused light. Features of the construction relate to ease of accessibility for the replacement of fluorescent lamps; and to a construction that can be easily and inexpensively installed, cleaned, repaired, removed or replaced.

Another object of the invention is to provide a hung luminous ceiling structure permitting free, natural and uniform circulation and distribution of air from spaces below the luminous ceiling into and through the plenum between the luminous ceiling and the structural ceiling of the room.

Another object of the invention is to provide a ceiling structure such that in advance of installation in a building the acoustical effect of the finished building may be predetermined to comport with a particular building condition so that the installation of the luminous ceiling complies with the infinite building variants to provide satisfactory acoustics.

Still another object is to provide a complete luminous ceiling construction in which all of the necessary details of the acoustics, the air conditioning, the lighting, the hangers, runners, splicers, clips, and other elements have been simplified, improved and perfected as a co-operating whole so that installation can be made easily and at much lower cost than has been the case.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views;

Figure 1 is a diagrammatic sectional view through a hung ceiling constructed in accordance with this invention;

Figure 2 is a fragmentary, bottom view of a portion of the ceiling as shown in Figure 1;

Figures 3, 4 and 5 are fragmentary, greatly enlarged, perspective views showing different constructions for the translucent sheets used in the ceiling shown in Figures 1 and 2;

Figure 6 is a sectional view showing a modification of the structure shown in Figure 4; l

Figure 7 is a sectional view showing another modified relation for the plastic sheeting from which the luminous ceiling is formed;

Figure 8 is a sectional view taken on the line 8-8 of Figure 1;

Figure 9 is a greatly enlarged sectional view taken on the line 9-9 of Figure 8;

Figures 10 and 11 are greatly enlarged sectional views taken on the lines 10-10 and 11--11, respectively, of Figures 8 and 10, respectively.

Figure 1 shows a part of the structure of a building including a structural ceiling 15 and beam 16, both of which may be made of concrete. A wall 18 extends downwardly from the beam 16. A luminous ceiling indicated generally by the reference character 20 has hangers 22 extending upwardly to the structural ceiling 15. The hangers 22 are held in a fixed spaced relation to one another by gauging struts 23. The cavity enclosed between the luminous ceiling 20 and the structural ceiling 15 will be referred to as the plenum 24.

In building construction, before the ceiling 20 is hung, the structure above the ceiling line is prepared by installing the necessary wire-ways, outlets, electrical boxes, fluorescent fixtures and lamps, air conditioning ducts, sprinklers, plumbing pipes and traps, hanger inserts, fasteners and other necessary equipment.

Figure 1 shows the surface of the structural ceiling 15 covered with acoustical material 26. Similar acoustical material 26 may be applied over the surface of the beam 16 and down the wall 18, if a very low noise level is desired. The far wall of the plenum 24, as well :as the other walls, are shown coated with acoustical material 26, the coating on the far wall being broken away for clearer illustration.

This sound-absorbing materal 26 is preferably white so as to reflect light, and if not itself white, it is preferably given a facing of white material which will not appreciably diminish the sound-absorbing value. This soundabsorbing material is uniformly distributed over surfaces of the plenum and may include the surfaces of ducts and other equipment located in the plenum. The thickness of the coating of sound-absorbing material 26 depends upon the material used and upon the noise reduction required. The use of such materials for rendering surfaces capable of acoustical absorption is well understood and no further explanation is necessary for a complete understanding of this invention.

Figure 1 shows fluorescent lamps 30 held in fittings 32 located between the hangers 22. None of the other structure or equipment of the building within the plenum 24 is shown in the drawings since it does not cooperate directly with the novel features of this invention and its illustration is not necessary for a complete understanding of this invention.

The hangers 22 have their upper ends connected directly to the structural ceiling 15. At the lower end of each hanger 22 there is a leveling strip 36 (Figure 8) having a slot 38 extending lengthwise of the strip. A bolt 40 extends through the slot 38 and through a hole in the hanger 22. The leveling strip 36, which is in effect an extension of the hanger 22, permits variation in the effective length of the hanger by loosening the bolt 40 and moving the leveling strip 36 upwardly or downwardly as permitted by the slot 38. A hanger clip 44 is connected to the lower end of each leveling strip 38 by a bolt 46 extending through a hole in the hanger clip 44 and through the slot 38 of the leveling strip 36.

The ends of the gauging struts 23 enter into the slots 0 38, there being threaded ends of reduced diameter extending through the slots with nuts 47 clamping the strips 3 a 36 to the shoulder at the full diameter portion of the gauging struts.

At the bottom of the hanger clip 44 there are alternating tabs 48 and 49 bent outwardly in different directions and curved to fit within runner molding 52. The runner molding 52 is made of metal, preferably resilient, and is of generally tubular cross section with an open seam at the top, and with the seam edges bent outwardly away from one another to form flanges 54.

The runner molding 52 is supported at spaced locations, as best shown in Figure 8; and, in the construction illustrated, is continuous across the entire length of the room. Other constructions can be used for panel ceilings and special effects. The flanges 54, of the runner molding 52, support plastic sheets 56 which provide the actual luminous area of the ceiling. In order to hold the plastic sheets 56 down on the flanges 54 of the runner molding, there are lofting clips 60 at spaced locations along the runner molding.

The construction of one of these lofting clips 60 is best shown in Figure 10. The lofting clip 60 is preferably made of metal with a center fold 62, upwardly extending portions 64 on opposite sides of the fold, and top flanges 66 extending in opposite directions from the upper ends of the portions 64. These flanges 66 overlie the plastic sheet material 56 and hold it down on the supporting flanges 54 of the runner molding 52.

The lofting clips 60 are pushed downwardly through the open seam at the top of the runner molding 52, and the downwardly extending portions 64 of the lofting clips 62 are held by friction against the confronting surfaces of the runner molding. This gripping action may be obtained in two ways, either by having the thickness of the lofting clips sufficient to distort or widen the open seam at the top of the runner molding so that the resilience of the runner molding causes it to grip the lofting clip; or by having the lofting clip 60 of resilient material and with the vertically extending portions 64 slightly spread from one another in their normal condition. In this latter case, the vertical portions 64 are thrust together when the lofting clip is pushed into the seam of the runner molding, and this distortion of the lofting clip produces the resilient force for gripping the lofting clip and holding it down by friction.

The advantages of this lofting clip construction, with the clip held down by friction with the runner molding, is that the flanges 66 can be adjusted to any desired position by merely pushing them down until they contact with the desired force against the top of the plastic sheets 56. The assembly can be made quickly and there are an infinite number of positions to which the flanges 66 can be adjusted.

The construction of the plastic sheets 56, which will be referred to as the diffusers, is an important part of this invention. Figure 3 shows one construction in which the diffuser S6 is formed with a series of panels in zigzag relation to one another and preferably at an angular relation of approximately 90. Other angular relations can be used. Each of the panels of the diffuser is pierced with a multitude of minute openings 70. By way of illustration, the openings may be from to 20 mils. These openings are shown arranged in rows, but they may be in any other relation to one another. They are made very small so as to be unnoticeable to one viewing the ceiling and they are preferably made by piercing the diffuser 56 without severing any material from the diffuser.

Figure 11 shows one of these pierced openings 70. The upwardly displaced sheet material forms a generally frusto-conical protuberance '72 with a ragged edge 74 where the material tears apart in response to the stretching caused by the piercing. Although some of the features of this invention can be combined in new combinations without the feature illustrated in Figure ,11, these 4 pierced openings have a number of important advantages for purposes of this invention.

One advantage is that the openings 70 are less noticeable when viewed from the bottom because they do not have any clearly defined edge in the plane of the panel surface in which the opening is formed. Another and more important advantage is that the upwardly displaced material acts as a shield to prevent direct rays of light from coming through the opening 70 and this also makes the openings less noticeable when viewed from below.

The pierced openings 70 reduce the cost of manufacture as compared with punched openings, and they are more practical with diffuser sheets which are bent along spacedapart lines, as in the construction shown in Figures 3-6, without the application of pressure to the surface between the localized lines of bending. Diffusers made of material which requires heat and more especially which also require pressure, to produce corrugated surfaces, such as shown in Figure 7, are not as well suited for use with the pierced openings 70 because the piercing is most effectively done when the sheet is flat, and the application of the heat and pressure impairs or destroys the protuberances formed by the piercing operation.

The openings 70 serve two important functions. One is that they permit sound to pass through the light diffuser 56, the large number of openings making the diffuser 56 relatively porous to sound waves. Another function is that air can pass easily through the light diffuser when such a porous effect is produced by having the myriads of small openings 70. This is particularly useful with ventilating and air conditioning systems where a distribution of air at low velocity over a very large area produces the most satisfactory and quietest results.

Figure 4 shows a modified construction in which a diffuser 56' is formed with panels in such angular relation as to produce channels instead of the zigzag cross section of Figure 3. In Figure 4 the openings 70 are shown confined to the vertical panels of the diffuser. This makes the openings 70 inconspicuous and leaves the horizontal surfaces of the diffuser 56 imperforate. It will be understood, however, that openings 70 can be provided in all of the panels shown in Figure 4 if desired; and also that because of the small scale of the drawing, only a few openings 70 are shown, these being merely representative of myriads of small pierced openings in the panels of the light diffuser 56.

Figure 5 shows two successive diffusers 56 located in such relation that the longitudinal edge of one overlaps the opposite longitudinal edge of the other with some clearance between the overlapping surfaces. This construction can be used where it is desired to still further increase the flow of air to or from the plenum; this clearance between overlapping edges of panels of the diffusers 56 can be obtained by having the overlapping panel at somewhat different angles from the other panels.

Figure 6 shows two diffusers 56 with their overlapping edges spaced from one another to provide additional area for the passage of air into and out of the plenum. The clearance between these diffusers 56' is obtained by having the vertical panel of one diffuser shorter than the corresponding vertical panel on the edge of the confronting diffuser.

Figure 7 shows two modified diffusers 56a. This construction differs from that of Figure 5 only in that the corrugated cross section of the diffusers 56a is curved instead of angular or channeled as shown in Figures 3-6. Longitudinal edges of adjoining diffusers 56a are spaced from one another in Figure 7 to provide more complete ventilation but it will be understood that the diffusers of Figures 3, 4 and 7 can be located adjacent to other diffusers without having any space between their longitudinal edges, and such a construction provides a more uniform illuminated area over the ceiling. It should be further understood that the undulating cross section shown in Figure 7 can be made with myriads of openings in the plastic sheet material, just as in the other diffusers described in connection with Figures 3 and 4.

The plastic light diffuser 56 can be made of a variety of translucent materials. By way of illustration, rigid vinyl sheets of .007 inch thickness, manufactured by the Bakelite Corporation, have been very effective. Sheets of styrene or methyl methacrylate can be used. The corrugations of the diffusers not only give them a decorative effect, but have the practical advantage of greatly increasing the stiffness of the diffusers so that'the runner moldings supporting them can be further apart.

The sound waves striking the diffusers from below pass through the openings 70 and are absorbed by the acoustical material 26 that coats the surfaces in the plenum. When space is provided between the longitudinal edges of successive diffusers as shown in Figures 5-7, sound waves also pass through these clearances, which provide louvres, and are absorbed by the acoustical coating in the plenum.

If the louvred construction of Figures 5-7 is to be used in a room where the acoustics have a predominant sound frequency, then the spacing of the louvres may be selected with that frequency considered. For example, if there is a predominant sound frequency around 1000 cycles, which has a wave length of roughly one foot, the ceiling is made to provide diffuser units roughly four inches Wide having a louvred sound passage on each edge of the unit of approximately one-half inch by thirtysix inches long evenly distributed throughout the ceiling area, and this is well within the limits of the ratio of open area to the length of the sound Wave for effecting substantially uninhibited passage of all sound waves through the luminous ceiling.

The preferred embodiments of the invention have been illustrated and described, but changes and modifications can be made and some features can be used in different combinations, for example uncorrugated panels, without departing from the invention as defined in the claims.

What is claimed is:

1. A luminous acoustical ceiling including a plurality of hangers connected to a structural ceiling at spaced locations along substantially parallel rows, a runner molding supported from the lower ends of the hangers of each row, a hanger clip connected to the bottom of each hanger and securing the runner molding to the hanger, translucent light diffusers supported by the runner moldings, the diffusers being corrugated plastic sheets which rest on the runner moldings, and lofting clips having flanges extending across the top of the corrugated plastic sheets and holding the plastic sheets down on the runner molding, and in which the runner molding is an open seam tube with the edges of the seam extending in 0pposite directions to form flanges supporting the light diffusers on opposite sides of the runner molding, and in which the corrugations of the light diffusers are formed by angularly related panels which connect with one another along straight fold lines, and there are myriads of minute openings extending through the panels to give the panels a porosity through which sound waves pass to the structural ceiling above the light diffusers, the openings having the material displaced therefrom disposed around the opening and forming a protuberance on the upper surface of the panel, and successive diffusers having their edge panels overlapping one another but spaced from one another to form louvres providing clearance for the passage of ventilating air and additional open spaces for the passage of sound waves through the luminous ceiling.

2. In a luminous ceiling having translucent light diffusers supported at ad istance below a structural ceiling to form a plenum with lights therein for illuminating the diffusers ,the improvements which comprises a construction in which the diffusers are made of solid and otherwise imperforate sheets with myriads of spaced openings through the solid material of the sheets for the passage of sound waves into the plenum, and a sound absorbing coating over the surfaces within the plenum and in which the corrugations of the light diffusers are formed by angularly related panels each of which makes an acute angle to the horizontal, and in which the openings in the angularly related panels of the corrugations are pierced openings and the material displaced forms a protuberance extending upwardly from the top surface of the corrugation and all of the displaced material is included in the protuberance.

3. In a luminous ceiling having translucent light diffusers supported at a distance below a structural ceiling to form a plenum with lights therein for illuminating the diffusers, the improvement which comprises a construction in which the diffusers are made of solid and otherwise imperforate sheets with myriads of spaced openings through the solid material of the sheets for the passage of sound waves into the plenum, and a sound absorbing coating over the surfaces within the plenum, and in which the corrugations of the diffusers are formed by angularly related panels, some of which are horizontal alternating with others that are vertical so as to form channels in the surface of the diffuser, and in which the openings in the corrugations are pierced openings with all of the material displaced from the opening forming a protuberance extending from the surface of the sheet material on the side of the sheet nearest to the light when the diffuser is in use.

4. In the luminous ceiling described in claim 3, the further improvement which comprises a construction in which the horizontal panels are imperforate and a construction in which the myriads of openings are confined to the vertical panels.

5. The luminous acoustical ceiling including diffusers made of translucent plastic sheets supported from a structural ceiling with a plenum located between the luminous ceiling and the structural ceiling for housing lights that illuminate the diffusers, an acoustical coating over top and side reflecting surfaces within the plenum, the plastic sheets having openings therein for the passage of sound waves into the plenum and into contact with the acoustical coating, and each of the panels of the luminous acoustical ceiling having a plurality of corrugations therein extending substantially parallel to longitudinal edges of the sheets, and there being also openings including spaces between the longitudinal edges of the sheets overlapping One another and spaced from one another and forming louvers for the passage of ventilating air and the sound waves through the luminous ceiling to the acoustical surfaces within the plenum, and in which the corrugations of the diffusers are formed by angularly related panels with myriads of small openings through the panels, the openings being pierced and the material displaced therefrom forming a protuberance extending from the surface of the sheet material on the side of the sheet which is uppermost when the diffuser is in use.

References Cited in the file of this patent UNITED STATES PATENTS 2,398,507 Rolph Apr. 16, l946 2,435,133 Behnke Oct. 18, 1949 2,659,808 Beckwith Nov. 17, 1953 2,680,502 Kurtzon June 8, 1954 2,698,071 Lee Dec. 28, 1954 2,734,126 Kruger Feb. 7, 1956 2,742,122 Stanley Apr. 17, 1956 2,803,741 Guth Aug. 20, 1957 2,817,752 Florence Dec. 24, 1957 2,850,109 Benjamin Sept. 2, 1958 FOREIGN PATENTS 617,131 Great Britain Feb. 1, 1949 693,097 Great Britain June 24, 1953 

